Iterative Postorder Traversal using one stack

[@sayakatta1836]

Anyone who has no idea about coding,he or she can easily understand what you are teaching. Amazing you are. Bring more and more videos

[@freemente4731]

This will give a stack underflow on the 3rd condition part.... as you pop the last item of the stack and the stack becomes empty.... the loop will check the top of the stack which does not exist causing a stack underflow...... solution to that will be to include a condition after the pop to see if the stack is empty or not.. For example : while(root==stack.top()->right) { root=stack.top(); std::cout

[@allan1827]

yep;)

[@anis_coc6227]

Actor 🔥🔥🔥🔥 best teacher ever !!!💪🦾💪💪🔥🦾🔥🦾🔥🔥🦾🔥🦾🔥🦾☠️☠️☠️

[@karthikk5895]

The condition 3 while loop needs a check whether the stack is empty or not.

[@bhagvatsinghrajput2313]

thank you so much sir you helped me a lot for understanding tree traversl

[@ramum5424]

Here, after traversing the children of subtree 'M', if you check for this condition if(p==top.right) { print(top.data); pop(); } At this instance we have only one element 'a'(THE ROOT) in the stack. Now in the 2nd condition, you're again pointing node p to 'A' right child which is 'M', which we've already traversed. Hence causing an infinite loop. So this algorithm works well until traversing the last right subtree of root. We will be able to get the output without the root node in the answer but in an infinite loop. SOLUTION: modify 2nd condition as: (q is a dummy node which points to null) if(!s.empty()) { if(q==stack.top().right) { p=stack.top(); //here p is the root node print(p.data); //prints the root node stack.pop(); //ending infinite loop (now the stack is empty) p=null; } else p=s.peek().right; } else p=null; }

[@tridevthakur5397]

Sir plz continue to make such useful video Thank u sir😊😊

[@DhananjayKumar-bd2jg]

great explanation!

[@batsunet]

I love your videos! You've helped me so much in my programming!

[@dmputube9]

p = root; while (true) { if (p) { push(p); p = p->left; continue; } if (isStackEmpty()) break; if (top()->right != null) { p = top()->right; continue; } // process node now currentNode = pop(); process(currentNode); if (! isStackEmpty() && top()->right == currentNode) { // avoid coming back to same node again and loop endlessly, process root of prior currentNode now currentNode = pop(); process(currentNode); } p = null; } believe this looks more clean, overall I trust iterative more than recursive. simply because I can still control size of stack, but not the stack size of recursion.

[@surajverma8687]

Nice explaination sir

[@ashishswaraj2351]

3rd condition if(p=Top().right) is correct this should go to the B element .. so I think it's wrong

[@durgashanker6491]

Hello Sir, can you please post tutorial on Recursion ?

[@aabhishek4911]

One basic doubt , How will you come to the conclusion that 2 nodes are not the same ? if their values or left and right child are not same ? what if 2 nodes having same value and both being the leaf nodes?

[@ucleminh1642]

How to use the Queue to Post-Order traversal binary tree

[@vijayhathimare4520]

if (top().right != null) then ?

[@allan1827]

nice explNATION

[@Understanding_the_world_withme]

Thank you sir

[@rafaelaraujo7351]

very good

[@uditagrawal6603]

Not working for binary tree : root=1, root.left = 2,root.right = 3, root.left.left = 4, root.left.right = 5,root.right.right = 6,root.left.left.left = 7

[@naveen-dd3hu]

Node root=new Node(1) root.left=new Node(2) root.left.left=new Node(4)

[@snehalumare4067]

Thank You....

[@punittiwari7557]

Sir please make a video on Morris Traversal please sir

[@svdfxd]

There is a video posted by Tushar Roy...

[@vinaysingh2089]

sir aap kaise h?? bahut din baad

[@vivekanandkhyade]

i m good vinay.....soory for the gap...now i can dedicate more time.....keep watching

[@an_son_mathew_]

💜

[@ArpitDhamija]

i slept 5 times while listening this

[@pruthvirajk6019]

Did he ask you to watch ! lol ! Dont play jokes.

[@samxsharan]

@Arpit 😂

[@hhcdghjjgsdrt235]

I slept 2 times while reading your lengthy informative comment

[@lalitkumarmehta6026]

Please provide code

[@Snehal_Javheri]

Could you please provide cpp code...Thank You !

[@Snehal_Javheri]

Sir I have designed code and executed...It is giving me segmentation fault...for STACK.TOP()->Right function....Please help me in this regards....Thank You ! Please send complete code- at [e-mail]

[@hhcdghjjgsdrt235]

I m new to coding and it may have some error. here it is C# void postOrDFS(TreeNode root) { Stack stack = new Stack(); stack.Push(root); HashSet prnted = new HashSet(); while (stack.Count!= 0) { TreeNode temp = stack.Peek(); if (temp.left != null && prnted.Contains(temp.left) == false) { stack.Push(temp.left); } else if (temp.right != null && prnted.Contains(temp.right) == false) { stack.Push(temp.right); } else { prnted.Add(stack.Pop()); Console.WriteLine(temp.val); } } }

[@srajensingh4532]

Are sir kaha chale gaye the

[@vivekanandkhyade]

soory for the gap...now i can dedicate more time.....keep watching

[@amanahmed6057]

Sir hindi me padaa do (*˘︶˘*).｡.:*♡

[@hhcdghjjgsdrt235]

English sikhlo, hindi ka koi value nei hae IT field me